Support mast



FIG. 1 is a perspective view of a support mast showing my new design;

FIG. 2 is a left side view thereof, the right side view being a mirror image thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof,

FIG. 5 is a front view thereof;

FIG. 6 is a rear view thereof; and,

FIG. 7 is a perspective view thereof with additional disclaimed environment showing an in-use position.

The broken-line showing of the top and bottom of the mast in FIGS. 1-7 and the horizontal extension and monitor in FIG. 7 is for illustrative purposes only and forms no part of the claimed design. The support mast is transversely broken to indicate that no particular length is claimed. 

The ornamental design for a support mast, as shown and described. 